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[46.53.134.188]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-488d5cf2e70sm27761365e9.0.2026.04.10.01.35.29 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 10 Apr 2026 01:35:30 -0700 (PDT) Date: Fri, 10 Apr 2026 11:37:23 +0300 From: Alexey Dobriyan To: "H.J. Lu" Cc: Florian Weimer , GNU C Library , linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, linux-api@vger.kernel.org Subject: Re: Avoid reading /sys/kernel/mm/transparent_hugepage/? Message-ID: References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Fri, Apr 10, 2026 at 03:40:30PM +0800, H.J. Lu wrote: > On Fri, Apr 10, 2026 at 3:28 PM Florian Weimer wrote: > > > > * H. J. Lu: > > > > > To enable THP segment load, ld.so opens and reads 2 files under > > > /sys/kernel/mm/transparent_hugepage/. This requires mounting > > > /sys and is expensive. Is it possible to put such info in vDSO? > > > > Alexey Dobriyan proposed adding AT_PAGE_SHIFT_LIST to the auxiliary > > Does it cover > > [hjl@gnu-tgl-3 linux]$ cat /sys/kernel/mm/transparent_hugepage/hpage_pmd_size > 2097152 > [hjl@gnu-tgl-3 linux]$ > > > vector a while back, but I don't know the status of that. Status: nothing happened. > How can we get > > [hjl@gnu-tgl-3 linux]$ cat /sys/kernel/mm/transparent_hugepage/enabled > always [madvise] never > [hjl@gnu-tgl-3 linux]$ This is not covered, see the link: https://lore.kernel.org/lkml/ecb049aa-bcac-45c7-bbb1-4612d094935a@p183/ PAGE_SHIFT_MASK should be folded into system call probably.